1. Field of the Invention
The present invention relates to a toner cartridge and an electrophotographic image forming apparatus. More particularly, the present invention relates to a toner cartridge having a control board mounted therein and an electrophotographic image forming apparatus using the same.
2. Description of the Related Art
In general, an image forming apparatus irradiates light onto a photosensitive medium charged to a uniform potential to form an electrostatic latent image corresponding to a desired image on the photosensitive medium, develops the electrostatic latent image using a toner to form a toner image, and transfers and fuses the toner image onto a sheet of paper, thereby forming the desired image.
A multi-color image forming apparatus generally requires yellow (Y), magenta (M), cyan (C), and black (K) toners. These color toners overlap each other to form a desired multi-color image. Accordingly, the multi-color image forming apparatus requires four developing cartridges for storing the respective color toners.
A multi-color image forming apparatus having four developing cartridges has a larger volume and a more complicated structure than a monochromic image forming apparatus for forming a single color image.
Furthermore, the developing cartridge has various components such as a developing roller for developing an electrostatic latent image as well as toner. When the toner is exhausted, the developing cartridge should be replaced with a new developing cartridge.
The life spans of the other components are longer than that of the toner. Accordingly, it is not economical to replace the developing cartridge with a new developing cartridge after the toner is exhausted, because the developing cartridge is replaced with a new developing cartridge even though the other components can still be used.
Accordingly, a method of separately supplying only a toner to use the developing cartridge until the life span of all components has been reached has been suggested. That is, the toner cartridge in which the toner is stored and the developing cartridge are separated, and, when the toner is exhausted, the toner cartridge is replaced with a new toner cartridge to supply the new toner. Thus, the developing cartridge is continuously used for the life span of the developing components.
This toner cartridge has a control board which can detect the life span of the toner. The toner board detects the depletion of toner stored in the toner cartridge and the other information regarding the toner cartridge and is generally attached to the outside of the toner cartridge.
The control board attached to the outside of the toner cartridge may be damaged by external impact due to, for example, a user's carelessness, and may be bumped against the other components when mounting or dismounting the toner cartridge. Also, the control board may be contaminated with foreign substances.
Accordingly, there is a need for an improved toner cartridge with a control board that is protected from external impacts, and an electrophotographic image forming apparatus using the same.